Proximity sensor devices are commonly used in electronic gear to turn power-consuming circuitries on or off in response to the proximity sensor device detecting something nearby. Use of proximity sensor devices in such applications may be particularly efficient because they may provide for detecting proximity without having to make physical contact. Proximity sensor devices are widely used in mobile phones nowadays. In such applications, proximity sensor devices are configured to turn off the Liquid Crystal Display (referred herein after as “LCD”) to prolong battery life when users place their mobile phones near their ears. For smart phones having LCDs with capacitive sensors, the proximity sensor devices may be configured to cut off the capacitive sensors to prevent unintended input due to contact of the skin and the LCD panels.
In some applications such as mobile phones, the proximity sensor devices may also be required to detect the presence of objects located very close to the proximity sensor devices. This may be an issue, as conventional proximity sensor devices are known to be susceptible to blind spot issue at close proximity. For such applications, it may be difficult to use such conventional proximity sensor devices to detect the external object positioned closely.
Proximity sensor devices may be formed as individual single integrated devices or alternatively may be assembled from pre-manufactured components. For example, proximity sensor devices may be assembled from packaged light-emitting devices and packaged detectors. The emitter and the detector may be assembled onto a printed circuit board (referred herein after as PCB) of an electronic device directly. For such proximity sensor assemblies, optical structures may be required to provide optical functionality needed for the proximity sensing. For example, the optical structures may be configured to direct light to a specific direction and not all directions.